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Liphistiidae are rarely seen, tube-dwelling spiders that construct rudimentary trap-doors, characterized by their downward pointing, daggerlike chelicerae,[2] and by having a segmented series of plates on the upper surface of their abdomens. Some make silk trip-lines radiating away from the burrow entrance. They are active at night and live for many years, and females molt after maturity. Adult males wander in search for females, which rarely leave their burrows. The respiratory system consists only of book lungs, which could be a reason why these spiders show a quite low level of activity.[3] In the past they were frequently believed to lack venom entirely, but in 2010 it was shown that at least Liphistius do have venom glands.[4]

Although most species live in burrows, cave-dwelling species also fasten their retreats to the cave walls. Both burrows and retreats are sealed with woven doors.[5]

The Malaysian trapdoor spiders are protected by local law. Continuous threats come from loss of habitat and collection by exotic pet traders. It is believed that most of the species are endemic henceforth once an isolated habitat is destroyed, the species might go into extinction.

Although they are Orthognatha (having downward pointing chelicerae), like the Mygalomorphae, there is no close relationship between those two. It is thought that the common ancestor of all spiders was orthognath, and that in the Opisthothelae, comprising Mygalomorphae (mostly tarantulas) and Araneomorphae (all other spiders), only the Araneomorphae changed their alignment of chelicerae, while the mygalomorphs retained this symplesiomorphic feature.[3]